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Loss determination in microsphere resonators by phase-shift cavity ring-down measurements.
J Barnes1, B Carver, J M Fraser
1Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
Optics Express
|August 20, 2008
Summary
This study measures optical loss in microresonator spheres using phase-shift cavity ring-down. This technique accurately determines optical lifetime and loss in whispering gallery modes.
Area of Science:
- Optics and Photonics
- Materials Science
Background:
- Whispering gallery modes (WGMs) in microresonators are sensitive to optical loss.
- Accurate determination of optical loss is crucial for microresonator applications.
Purpose of the Study:
- To determine the optical loss of whispering gallery modes in microresonator spheres.
- To validate a phase-shift cavity ring-down technique for optical loss measurements.
Main Methods:
- Utilized phase-shift cavity ring-down technique for optical lifetime measurements.
- Measured amplitude modulation phase difference between input and scattered light.
- Measured phase lag of light exiting the coupling waveguide.
Main Results:
- Successfully extracted ring-down times and optical loss.
- Optical loss measurements were consistent with theoretical models.
- Interference between cavity modes and waveguide propagation fully described the observed phenomena.
Conclusions:
- Phase-shift cavity ring-down is an effective method for quantifying optical loss in microresonator spheres.
- The developed model accurately describes the optical behavior of the system.
- This work contributes to the precise characterization of micro-optical devices.
